1. Field of the Invention
This invention relates to electret microphones, and more particularly to miniature electret microphones and methods for manufacturing miniature electret microphones.
2. Description of Related Art
An electret is a dielectric that produces a permanent external electric field which results from permanent ordering of molecular dipoles or from stable uncompensated surface or space charge. Electrets have been the subject of study for their charge storage characteristics as well as for their application in a wide variety of devices such as acoustic transducers (including, for example, hearing aids), electrographic devices, and photocopy machines.
A number of electret microphone designs exist. However, small, high quality electret microphones tend to be quite expensive. Therefore, a need exists for small, high quality, inexpensive electrets, particularly electret microphones. The present invention meets these needs.